This application relates to window screens for inclusion into windows commonly known as double hung which comprise an upper moving sash and a bottom moving sash that operate by translating up and down, the bottom sash directly to the room side of the upper sash, and more specifically such windows that are furnished with hardware to allow the moving sashes to tilt their tops inward in order to facilitate cleaning of the exterior glass from inside the building.
When double hung windows are opened to pass air from the outdoors they are protected from the intrusion of flying insects with fabric screens. Besides the familiar designs where window makers attach screen fabric in rigid frames to the exterior of their window assemblies, several products are manufactured to provide retractable, rollup screens that operate within a frame applied around the perimeter of an installed window.
Several patents have been issued for vertical as well as horizontal sliding window assemblies that incorporate retractable, rollup screens, as does the design presented herein. Those patents commonly present details about how their rollup mechanisms are to work. However, the rollup mechanisms presented herein are not dependent on any of the claims of those devices and the rollup mechanisms for the design disclosed herein may be any of the rollup mechanisms commonly available on the market.
Several patents have also been issued for window assemblies with retractable, rollup screen mechanisms incorporated either into their sashes or into their perimeter frame assemblies or both, as does the design presented herein. The closest of these designs to the design presented herein is the first embodiment of U.S. Pat. No. 5,915,443 (1999), to Jack Lindley, Jr., which discloses a double hung window with a rollup insect screen mounted inside the bottom rail member of its bottom moving sash with its screen attached to the window sill, just as the design presented herein. However, the free edges of the screen in that embodiment, that is the edges stretching between the screen rollup mechanism and the window sill, are not protected from intrusion of insects, the fabric being left with each of its vertical edges running free at unspecified distances from the faces of the adjacent jamb members in the surrounding window frame.
Additionally in that embodiment, Lindley presents what he calls a pivotable flap attached to the lower sash and enclosed by the meeting rails, very much like the fin baffle presented herein; however, the design presented herein attaches that fin baffle to the opposite meeting rail and uses said fin baffle for a purpose not anticipated by the Lindley embodiment; that is, it is used to close off the gap between the lower sash and the upper sash that occurs when the lower sash is tilted for cleaning and, therefore, the fin baffle for the design presented herein is not the same as the pivotable flap presented by Lindley.
Lindley also discloses in that U.S. Pat. No. 5,915,443 another embodiment wherein a rollup screen is dispensed from a roller mounted onto the window sill at its room side, with the translating horizontal end of the screen fabric attached to the bottom of the bottom sash, as with an alternate design embodiment presented herein. Lindley, with that embodiment, protected the free edges of the screen fabric from insect intrusion by providing a track to enclose said edges. However, the alternate design embodiment presented herein, although it appears similar, does not require such a track. Also, the placement of the screen rollup mechanism presented herein improves on the Lindley design by being upside down from said embodiment, which upside down placement protects the rollup mechanism, unlike the Lindley design, from accumulations of wind-blown rain and snow that can corrode working parts.
All of the rollup screen systems I can find in the patent literature, except for the first embodiment of the Lindley design, attempt to address the problem of how the free edges of their screen fabric may be provided with a secure deterrent to the passage of flying insects. Universally, those patents conceive to solve the problem by either a means of attaching those edges to the window jambs or by providing some sort of track system enclosing those edges; but such track systems and attachment systems always require devices to be fitted to the window jambs, which devices inhibit the tilting of sashes for cleaning.
The only exception I have found to these two concepts for protecting such free edges is in the Screen Away products of the Larson Manufacturing Company of South Dakota, illustrated in FIG. 13, which products form the insect seal by stretching the free edges of the screen fabric across the face of fiber pile weatherstripping, with such weatherstripping being mounted to the weather side of the screen fabric on a rigid fin affixed to the window jamb, parallel to the plane of the screen fabric and with the opposite face of the screen fabric being confined by a structure provided for an adjacent sliding sash. That, in effect, places the edge of the Larson screen fabric in a track-like enclosure such that if, for the sake of argument, the sliding Screen Away sash were to be made so that it could tilt, the fabric would require being withdrawn from its track-like enclosure and reinserted in order to complete tilt-to-clean window washing. My experience with said Screen Away products reveals that although said withdrawal and reinsertion is rather easy remote from the rollup roller, it is impossible near to the rollup roller without tearing the screen fabric and, thus, the Screen Away design cannot be conceived to be suitable for tilt-to-clean windows.
The design presented herein, however, is suitable for tilt-to-clean windows; that is, the person washing a tilt-to-clean window fitted as disclosed herein will be able to tilt and clean the sash as with typical tilt-to-clean windows except for one or two quickly accomplished additional procedures of minimal effort, none of which require tools.
In conclusion, in so far as I am aware, no bottom sash of a hung window of the tilt-to-clean variety has ever been protected against intrusion of flying insects by having a self-storing rollup insect screen incorporated into the bottom rail of said sash or incorporated to the room side of its sill such that the insect screen is rolled out to protect the ventilation opening in the same operation that moving of the lower sash creates such ventilation opening, while also not requiring any rearrangement of the insect protection components in order for the lower sash to be tilted for the convenient cleaning of its exterior glass surfaces.
Nor do I believe that there has ever been an upper sash for a double hung window of the tilt-to-clean variety protected against intrusion of flying insects by having a self-storing rollup insect screen incorporated into the head frame of the window such that the insect screen is rolled out to protect the ventilation opening in the same operation that moving of the upper sash creates such ventilation opening, while also providing during the tilting of the upper sash for the convenient cleaning of its exterior glass surfaces, an expedient means of transporting the bottom end of said screen from the top of said sash to the bottom of said sash along its weather side by incorporating guide tracks into the sash or by clip attachment-and-reattachment systems.